Paul l



P. L. MARDISVAND A. 1. HALL.

CONTROL SYSTEM.

APPLICATION FILED Jun: 13. 1911.

Patented July 1, 1919.

ATTORNEY I UNITED STATES PATENT OFFICE.

-.' CONTROL SYSTEM.

1308,0851 Specification of Letters Patent. Patented J ly 1, 1919 Application filed June 13, 1917. Serial No. 174,448.

. To all whom it may concern: nor to vary the excitation, automatically or 55 Be it known that we, PAUL L. MARnIs, a at will, of a dynamo-electricgenerator.

citizen of the United States, and a resident In the accompanying drawing, Figure l is of \Vilkinsburg, in the county of Allegheny a diagrammatic View of a control system and State of Pennsylvania, and ARTHUR J. embodying our invention, and Fig. 2 is a HALL, a subject of the King of England, and plan view of a fluid device for operating the 6 a resident of VVilkinsburg, in the county main controller illustrated in Fig. 1 of the of Allegheny and State of Pennsylvania, drawing. have invented a new and useful Improvement Referring to Fig. 1 of the drawing, a genin Control Systems, of which the following erator 1, embodying an armature 2 and a is a specification. field winding 3, is provided .with an excit- 6 Our invention relates to systems of control ing generator 4 having an armature 5 and a and particularly to systems of control for field winding 6. In circuit with the exciting governing the operation of dynamo-electric generator 4 and the field winding 3 of the generators. generator 1 are a plurality of resistors One object of our invention isto provide R1 to R10, inclusive, for varying the excitaa control system that shall govern the exoition of the generator 1. tation of a dynamo electric generator in a A main controller 7 embodying a rheostat simple and an improved manner. drum 8 for short circuiting the resistors R1 to 20 Another object of our invention is to pro- R10, inclusive, and an interlock drum 9, for a vide a control system having a dynamo-elecpurpose to be described later, are adapted to 7 tric generator therein that shall have the be operated by a fluid device PK and to be excitation thereof varied automatically and controlled by a master switch MS. at will under the control of a main COD", The rhcostat drum 8 embodies a contact 2 troller governed by a master switch. segment 10 which is adapted to engage con- Another object of our invention is to protact fingers 11 to '21, inclusive, when the vide a control system of the above-indicated main controller is moved through positions character that shall embody a main controla to f, inclusive, and the interlock drum emler having a rheostat drum for varying the bodies two contact segments 2 and 23 WhlCl'! 50 excitation of an electric generator and an inare adapted to engage the cont-act fingers'24 terlock drum and a master switch for govto 33, inclusive, when the main controller is erning the operation of the main controller. moved through positions a to f, inclusive.

More specifically, our invention embodies The apparatus PK embodies a rack 35 a dynamo-electric generator having an exwhich engages a pinion 36 mounted on the 15 citing generator associated therewith that is shaft of the main controller 7and is progoverned by a main controller in accordance vided with pistons 37 and 38 which operate with the movement of a master switch, the within the cylinders 39 and 40. The cylinmaster switch being adapted to increase the ders 39 and 40 are respectively provided excitation, automaticall and at will, of the with magnet valves 41 and 42 for govern- I) dynamo-electric generator when moving in ing the admission and release of air pressure one direction and to reduce the excitation, to and from them. The magnet valve 41 is automatically and at will, of the dynamoprovided with an "operating coil 43 that is electric generator when the master switch adapted to connect the cylinder 39 to an air is moved in a reverse direction. 5 supply 44, When in the released position, and

.In many power-plant installations now in. to exhaust the air pressure within the cylin- 7 service, it isessential to provide pilot motors der 39 through a port 45, when in an operafor varying the resistors in the generatortire position. The magnet valve 42 is profield circuit and, by reason thereof, it is, in vided with an operating coil 46 and is adaptmany cases, difficult to govern the generatored to connect the cylinder 40 to the air supfield excitation in a positive and an accurate ply 47 when in a released position and to exmanner. haust the air pressure within the cylinder 40 108 In a system embodying our invention, a through a port 48 when in an operative posix-position master switch is associated with sition. The apparatus PK thus moves in a. fluid-operated main controller in a m-anthe one or the other direction, dependent because, when upon the particular magnet valve that is energized, the movement being toward the energized or closed (to the air supply) valve. A positive stopping of the main controller in the operative positions thereof is insured,

the active magnet valve is deenergized, which occurs in each controller position, as subsequently described in -detail. high-pressure balanced conditions obtain in the apparatus, and the movement is immediately arrested.

T he inaster switch MS embodies a contact arm 49 which is adapted to engage contact fingers 50, 51, .32 and 53 when moved through positions a, b and c to eifect movement of the main controller 7 in a forward directionand to engagecont-act'fingers 54, 56 and 57 when moved through positions (I, c and f to efi'ect movement of the main controller 7 in a reverse direction. A switch (")0 is pro vided for connecting a battery B to the auxiliary control circuits associated with the master switch MS and the apparatus PK.

The master switch MS, when in position a, is adapted to effect automatic movement of the main controller 7 in a forward direc tion in order to short circuit the resistors R1 to R10. inclusive, and when oscillated between positions I) and c, it is adapted to move the controller 7 in a forward direction in a step-by-step manner in order to effect an increased energization of the generator 1. hen the master switch is oscillated between positions (I and c, the main controller 7 is moved in a reverse direction in a step by-step manner, and, when the master switch is moved to position f, the main con troller 7 is automatically moved in a reverse direction to insert the resistors R1 to R10. inclusive, in the circuit of the exciting generator 4 and of the generator field winding 3.

Assuming the apparatus to be in the position illustrated in Fig. 1. the main controller 7 may be advanced in a step-hy-stcp manner and the resistors R1 to R10. inclusive, excluded from the circuit of the exciting generator 4 and of the field winding 3 as follows: \Vhcn the contact arm 49 is moved to position 0 to engage contact finger 50, a circuit is completed through the coil i of the magnet valve 41. which may be traced from one terminal of the battery B through the contact arm 49. contact finger 50, contact fingers 27 and 2S-which are bridged by the contact segment '22coil 43 of the magnet valve 41 and the switch 60 to the other terminal of the battery 13. Thus. the magnet valve 41 is operated to release the air pressure contained within the cylinder 39 and to permit the air pressure acting on the piston 38 to move the apparatus PK and the main controller 7 to osition b. In position I; of the main confinger '27 is disengaged troller, the contact from contact with the contact segment "22 in order to denergize the coil 43 of the magnet 41. The resistor drum 8, in moving from position a to position Z), short circuits the resistors R1 and R2.

\Vhen the contact arm 49 is moved from position 0 to position b, a circuit is completed through the coil 48 of the magnet alve 41 which may be traced from one terminal of the battery B through the switch 60, contact arm 49, contact finger 51, contact fingers 24 and '28-which are bridged by the contact segment 2-2and the coil 43 or the magnet valve 41 and the switch 80 to the other terminal of the battery B. Thus, the magnet valve 41 is operated to again release the pressure within the cylinder 39 and perniitj'thc main controller 7 to be advanced from position I) to position 0. In position a of the main controller. the contact finger 24 is disengaged from the contact segment 22 to deenergize the coil 43 of the magnet. valve 41 and prevent further movement of the main controller, and the contact segment 10 of the resistor drum 8 is adapted to shortcircuit the resistors R3 and R4 which are included in the circuit of the exciting generator 4.

In a similar manner, the main controller is moved through positions (I, c and f, and the resistors R5 to R10, inclusive, are ex cluded from the circuit of the exciting generator 4. V

In case it is desired to automatically move the controller 7 in a forward direction from position a to positon f, the contact arm 49 of the master switch MS is moved to position a in order to connect the contact fingers 5:? and to the battery B. Thus, the contact fingers 24 to 27, inclusive, which are associated with the main controller 7, are directly connected to the battery B, and one of the same maintains a closed circuit through the coil 43 of the magnet valve 41 for moving the main controller in a forward direction until position is reached. In position the contact segment '22 becomes disengaged from contact with the contact fingers 24 to 27, inclusive.

Assuming the master switch to be in position-e and the main controller in position f and it is desired to move the main controller in a reverse direction at will. the 701% tact arm 49 of the main switch is moved from position c to position (I in order to complete a circuit through the coil 46 of the magnet-valve 42. The circuit through the coil 46 extends from one terminal of the battery B through switch 60, contact arm 4 contact finger 56, contact fingers 29 and which are bridged by the contact segment 23coil 46, and the switch 60 to the other terminal of the battery B. Thus, the magnet valve 42 is energized to effect movement of the main cont-roller from position f to position e, at which point the contact segment 23 is disengaged from contact with the con tact finger 30 to break the circuit of the coil 46 and prevent further movement of the apparatus PK and the controller 7.

\Vhen the contact arm 49 is moved from position at to position 6, a circuit is completed through the coil 46 of the magnet valve 42 from one terminal of thebattery B through. the contact arm 49, contact finger 55. cont-act fingers 33 and 29which are bridged by the Contact segment 23coil 46 and the switch 60 to the other terminal of the battery B. Thus, the magnet valve 42 is again operated and the controller 7 is re-.

versed from position 0 to position cl, and, in a similar manner, when the main controller is reversed through positions a, b and a.

vIn case the main controller 7 is in position f, and it is desired to automatically and continuously move the same in a reverse direction to position a, the contact arm 49 ot the master controller MS is moved to position f, in order to maintain a closed circuit from. thebattery B through the coil 46 of the magnet valve 42. The circuit through the coil 46 extends through one of the contact fingers 30 to 33, inclusive, contact Segment 23 and the coil 46 of the magnet valve 42. The magnet valve 42 is maintained in an operative position until the main'controller 7- is moved to position a.

Frointhe above description, it will be noted that the excitation of the gene 'ator 1 is continuouslyand automatically increased when the contact arm 49 of the master" switch is imposition-a; that the excitation of the generator 1 'is constantly decreased if the contact arm 49 is in position f; that the oscillation of the contact arm 49 between positions "5 and c of the masterswitch will Y increase the excitation of the generator in stepb v-step manner, and that the OSCll tion of the contact arm 49 between positions.

(Z and o of the master switch will reduce the excitation of the generator 1 in a step-bystep manner.

Modifications in the system and arrangement and location of parts may be made within the spirit and scope of our invention and such modifications are intended to be covered by the appended claims.

We claim as our invention:

1. In a system of control for adynamoelectric machine, the combination with a main controller having a rheostat drum for governing the excitation of the dynamoelectric machine, an interlock drum for governing the movement of the controller, and a fluid motor for operating the controller, of a six-position switch associated with said interlock drum and the fluid motor for moving the main controller automatically and at will in a forward and in a reverse direction.

2. In a system of control, the combination the dynamo-electric machine, of means comprising a master switch for advancing the main controller at will in a forward dire tion when oscillated between I, positions thereof and for moving the main controller at will in a reverse direction when oscillated between two other operative positions thereof.

3 In a system of control, the combination with a dynamo-electric machine, and a main controller having a rheostat drum for governing the excitation of the dynamo-electric machine, an interlock drum, and a fluid irotor associated with said interlock drum, of means comprising a master switch associated with said interlock drum and the fluid motor for moving the main controller at will in a forward direction when oscillated between two of the operative positions thereof and for automatically moving the main controller in a forward direction when moved to a third operative position thereof.

4. In a system of control, the combination with a dynamo-electric machine and a main two opera-ti;

controller for governing the excitation of they with a dynamo-electric machine, a main controller for governing the excitation of the dynamo-electric machine, and a fluid motor ai ing two magnet valves for governing the pe ation of the controller, of a master controller having means associated therewith for operating one of said magnet valves to advance the main controller at will in a forward direction when the master switch is oscillated between two of the operative positions thereof.

6. In a system of control, the combination with a dynamo-electric machine, a'main controller for governing the operation of the dynamo-electric machine, and a fluid motor having two magnet valves for operating the main controller, of a master switch having means associated therewith for opcrating one of said magnet val vcs to advance the main controller automatically and at will in a forward direction and for operat ing the other magnet valve to reverse the main controller. automatically and at will.

7. In a system of control, the combination with a dynamo-electric machine, a main controller having a rheosta t drum for governin the excitation of the dynamo-electric machine, an interlock drum associated with he rheostat drum, and a fluid motor having .o magnet valves for operating the main controller, of a six-position master switch associated with said interlock drum for selectively operating said magnet valves to move the main controller automatically and at will in a forward and in a reverse direction.

S. In a system of control, the combination with a dynamo-electric machine and a main controller for governing the dynaino-electrle machine and provided with a rheostat and PAUL L. MARDIS. ARTHUR J. HALL. 

